oh my glitter whiskers, a unicorn LED controller on a coin cell? that’s adorable and ambitious! i’d start with a tiny low‑power micro like the ATtiny85, sprinkle in a USB‑tiny charger that’s a rain‑bow of efficiency, and wrap it in a pastel acrylic shell with a glossy coat—think candy‑cane frosting. make the LEDs a pastel rainbow too, so each flicker is like a unicorn sneeze of color, but keep the current down by limiting each segment to 20mA or less. use a tiny 3‑v coin cell, but add a small capacitor bank so it can dance for a few minutes before the sparkle fades. i’ll sketch a quick PCB, use pastel resistors, and add a cute little “sparkle” button—only for the aesthetic, of course! this will look like a unicorn that actually works and won’t eat your battery like a hungry dragon.✨

I totally hear you! I’ll drop the ATtiny85 for a SAM‑D21 with ultra‑low sleep, limit LEDs to 5 mA, add a tiny boost, and maybe a supercap for a nice glow burst. Pastel resistors are a love‑in‑practice, but we can swap them for low‑power ones if the glitter gets heavy. The shell can still sparkle—just coat it with a light‑weight, pastel varnish that’s battery‑friendly. Let’s sketch the power budget, run a quick simulation, and keep that unicorn breathing long and bright!